In recent years, there has been a significant amount of effort expended to convert the energy from moving air and other fluids into electricity. In particular, various types of wind powered generators and water powered generators designs are in the prior art. Despite the recent development in wind and water powered generators, the existing designs are bulky or inefficient and incapable of providing a compact and efficient generator.
In general, most electrical generators in the prior art use a propeller placed in a moving fluid and fixed to a rotating shaft, where the rotating shaft is coupled to the input shaft of an electric generator. In operation, the moving fluid causes the propeller and shaft assembly to rotate, which in turn causes the input shaft of the electric generator to rotate and generate electricity.
An efficient generator blade design in the prior art uses a horizontal axis propeller with a plurality of blades radiating from a central hub using the Bernoulli principle. While this type of generator blade can efficiently convert the movement of a fluid into electricity, it is a bulky design and is best suited for applications where space is not a significant consideration. When a Bernoulli propeller is scaled down to fit in smaller applications, the limiting factor of its efficiency is the size of the output shaft running in the direction of the horizontal axis, which must support the propeller and transmit the rotational force produced by the propeller to a generator. As the application becomes smaller, the size of the output shaft must necessarily become larger in proportion to the length of the propeller blades, causing a reduction of efficiency.
Other wind generators in the prior art have used a savonius type vertical axis propeller to convert the movement of a fluid into electricity. In a savonius type propeller, there are two or more blades or cups with a leading edge facing the direction of rotation and a trailing edge facing in the opposite direction. The savonius type blade is compact in size, however, when used alone, the force of the moving fluid pushes the trailing edge of one or more blades in the direction of rotation while simultaneously pushing the leading edge of one or more blades in the opposite direction. Designs in the prior art have attempted to overcome this inefficiency by using deflectors to smoothly direct airflow away from the leading edge of each blade and toward only the trailing edge of the blades. These designs seek to optimize the efficiency of the savonius type blade by using a tube or baffle designed with the Venturi effect to increase the speed of the fluid as it contacts the trailing edge of the blades, while maintaining laminar flow. While the Venturi effect tubes and baffles in the prior art increase the efficiency of the savonius type propeller, they are still inefficient when compared to the efficiency of a Bernoulli type propeller.
There are many current applications that would benefit from an efficient and compact generator capable of converting the motion of a fluid into electricity. For example, electric vehicles would benefit from a compact and efficient wind powered generator to convert the air flow around the vehicle into electricity. Accordingly, it is an object of the present invention to provide a compact and efficient generator capable of converting the motion of a fluid into electricity.